Binocular with interocular adjustment while maintaining objective lenses spacing constant

ABSTRACT

A binocular comprising a binocular body, one or a pair of objective lens-barrel unit or units, a pair of eyepiece lens-barrels and a pair of image-erecting chambers. A pair of parallel optical axes pass through the objective lens-barrel unit or units. The image-erecting chambers are arranged between the objective lens-barrel unit or units and the eyepiece lens-barrels. The image-erecting chambers have incorporated therein their respective prism units for optically connecting the optical axes of the objective lens-barrel unit or units to respective optical axes of the eyepiece lens-barrel units. Each of the image-erecting chambers is associated with the binocular body for angular movement relative thereto about a corresponding one of the optical axes of the objective lens-barrel unit or units in such a manner that the optical axes of the respective eyepiece lens-barrel units are movable angularly toward and away from each other respectively about the optical axes of the objective lens-barrel unit or units.

This application is a continuation of application Ser. No. 07/225,749,filed Jul. 29, 1988 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates generally to binoculars, and more particularly,to a binocular comprising a pair of image-erecting chambers each havingincorporated therein a Porro prism or a Porro mirror.

In general, a binocular comprises a pair of right- and left-handlens-barrels units. Each of the lens-barrel units includes an objectivelens-barrel having incorporated therein an objective lens system, and aneyepiece lens-barrel having incorporated therein an eyepiece lenssystem. The objective lens system has an optical axis extending incoaxial relation to that of the eyepiece lens-barrel.

The binocular comprises an intereyepiece-distance adjusting mechanismfor adjusting the distance between the eyepiece lens systems of therespective lens-barrel units to match the distance between theobserver's eyes. The adjusting mechanism includes a single-shaft type ora two-shaft type.

FIG. 1 of the accompanying drawings illustrates an example of a priorart binocular of single-shaft type. The binocular comprises a pair oflens-barrel units 11 and 12 having their respective eyepiecelens-barrels 11a and 12a. Support arms 11b and 12b of the respectivelens-barrel units 11 and 12 are mounted on a hollow support shaft 14 forangular movement about an axis thereof. The support shaft 14 is mountedon a focusing central shaft 13 in concentric relation thereto. Thearrangement is such that the pair of lens-barrel units 11 and 12 aremoved toward and away from each other angularly about the axis of thesupport shaft 14, thereby adjusting the distance between the eyepiecelens-barrels 11a and 12a to match the distance between the observer'seyes.

The central shaft 13 has an operating roller 15 threadedly engaged onone end thereof. A pair of levers 16 and 17 are mounted on the other endportion of the central shaft 13 for angular movement about the axis ofthe central shaft but precluding movement along the axis of the centralshaft. Angular movement of the operating roller 15 causes the centralshaft 13 to be moved within the hollow support shaft 14 along the axisthereof, so that the pair of levers 16 and 17 are also moved togetherwith the central shaft 13. Movement of the levers 16 and 17 in turncauses the pair of eyepiece lens-barrels 11a and 12a to be movedrelatively to the respective objective lens-barrels, thereby adjustingthe focus of the binocular.

The binocular described above with reference to FIG. 1 is relativelycomplicated in structure, and is relatively cumbersome in assembling thevarious component parts. Specifically, the support shaft 14 swingablysupporting the pair of lens-barrel units 11 and 12, and the centralshaft 13 for adjustment of the focus are formed into a double-shaftstructure. In addition, the right- and left-hand levers 16 and 17 foradjustment of the focus are mounted on the central shaft 13. In thismanner, the intereyepiece-distance adjusting mechanism and the focusingmechanism are assembled in a united fashion. By this reason, thebinocular is complicated in structure and is troublesome in assemblingthe various component parts.

FIGS. 2 and 3 illustrate an example of a prior art binocular oftwo-shaft type. The binocular comprises a body 22 and a pair oflens-barrel units 21 and 24. A pair of transmission shafts 23 and 25 aremounted to the body 22. The pair of lens-barrel units 21 and 24 aremounted respectively to the transmission shafts 23 and 25 for angularmovement about their respective axes, thereby adjusting the distancebetween optical axes of the respective lens-barrel units 21 and 24.

Specifically, the transmission shaft 23 has one end thereof whichextends into a hinge section 21a of the lens-barrel unit 21 which islocated adjacent the objective lens system. A small ball 30 is arrangedat a hinge section 21b of the lens-barrel unit 21 which is locatedadjacent the eyepiece lens system. These hinge sections 21a and 21b forma support for the transmission shaft 23. The right-hand lens-barrel unit24 is constructed in the same manner as the left-hand lens-barrel unit21.

A cross-plate 26 is arranged within the body 22 and has opposite endswhich engage respectively with the transmission shafts 23 and 25. Thecross-plate 26 is threadedly engaged at its center with a spindle 28which is angularly movable about its axis together with an operatingroller 27.

Angular movement of the operating roller 27 causes the spindle 28 to bemoved angularly about its axis so that the cross-plate 26 is moved alongthe axis of the spindle 28. By the movement of the cross-plate 26, thetransmission shafts 23 and 25 are moved along their respective axes. Themovement of the transmission shaft 23 along its axis is transmitted tothe objective lens-barrel of the left-hand lens-barrel unit 21 throughan interlocking arm 29, to displace the objective lens-barrel relativeto the eyepiece lens-barrel, thereby adjusting the focus of theleft-hand lens-barrel unit 21. The right-hand lens-barrel unit 24 isalso adjusted in focus in the same manner as the left-hand lens-barrelunit 24.

The binocular of two-shaft type illustrated in FIGS. 2 and 3 hasproblems similar to those of the binocular of single-shaft typedescribed previously. That is, the two transmission shafts 23 and 25serve as a pivoting arrangement for adjustment of the intereyepiecedistance, and also serve as a driving-force transmitting arrangement foradjustment of the focus. Thus, also in the binocular shown in FIGS. 2and 3, the intereyepiece-distance adjusting mechanism and the focusingmechanism are assembled in a united fashion.

As described above, the arrangement of the conventional binocular issuch that in the case of the single-shaft type, the pair of lens-barrelunits are angularly moved about a pivotal axis parallel to the opticalaxes of the respective lens-barrel units, while in the case of thetwo-shaft type, the pair of lens-barrel units are angularly movedrespectively about a pair of pivotal axes parallel to the respectiveoptical axes of the lens-barrel units in order to adjust theintereyepiece distance to match the distance between the observer'seyes. Because of the arrangement of the conventional binocular, when thepair of lens-barrel units are moved angularly toward and away from eachother to adjust the intereyepiece distance, the optical axes of therespective objective lens systems are also moved angularly, resulting ina variation in the distance between the optical axes of the respectiveobjective lens systems. This makes it difficult to regulate the pair ofoptical axes with a high accuracy in assembling of the binocular.Moreover, it is impossible to incorporate a flat plate-like polarizingfilter or the like in the binocular in relation common to the pair oflens-barrel units.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide an improvedbinocular capable of maintaining the distance between the pair ofobjective lens systems constant regardless of adjustment of theintereyepiece distance.

For the above purpose, according to the invention, there is provided abinocular comprising:

a binocular body;

a lens-barrel having an objective lens positioned within the barrel, theobjective lens-barrel being mounted on the binocular body and having apair of optical axes passing through the objective lens in parallelrelation to each other;

a pair of eyepiece lens-barrels including respective eyepiece lenses,each eyepiece lens having respective optical axes extending parallel andoffset to the respective optical axes of the objective lens; and

a pair of image-erecting chambers, each chamber being arranged betweenan objective lens-barrel and a corresponding one of the eyepiecelens-barrels, the eyepiece lens-barrels being mounted, respectively,onto the pair of image-erecting chambers, thereby forming an eyepiecelens-barrel unit, the pair of image-erecting chambers includingrespective optical means for optically connecting the optical axes ofthe objective lens with the optical axes of the respective eyepiece lensmeans,

wherein each of the pair of image-erecting chambers is adapted toangularly move with respect to the binocular body, about a correspondingone of the pair of optical axes of the objective lens in such a mannerthat the optical axes of the respective eyepiece lens are movablerespectively toward and away from each other about the pair of opticalaxes of the objective lenses.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a partially broken-away top plan view of a binocular ofsingle-shaft type according to the prior art;

FIG. 2 is a partially broken-away top plan view of a binocular oftwo-shaft type according to the prior art;

FIG. 3 is a cross-sectional view taken along the line III--III in FIG.2;

FIG. 4 is a partially broken-away top plan view of a binocular embodyingthe invention;

FIG. 5 is a rear elevational view of the binocular illustrated in FIG. 4as viewed from the side of a pair of eyepiece lens-barrels;

FIG. 6 is a front elevational view of the binocular illustrated in FIG.4 as viewed from the side of a pair of objective lens-barrels;

FIG. 7 is a fragmentary view of one of the pair of objectivelens-barrels illustrated in FIGS. 5 and 6;

FIG. 8 is an exploded perspective view of the binocular illustrated inFIGS. 4 through 7, with the right-hand lens-barrel unit omitted fromillustration;

FIG. 9 is a top plan view of a binocular according to a modification ofthe invention;

FIG. 10 is a partially broken-away rear elevational view of thebinocular illustrated in FIG. 9 as viewed from the side of a pair ofeyepiece lens-barrels, showing an interlocking mechanism;

FIG. 11 is a fragmentary view of one of the eyepiece lens-barrels shownin FIG. 10;

FIG. 12 is an exploded perspective view of the binocular illustrated inFIG. 9, with a right-hand lens-barrel unit omitted from illustration;

FIG. 13 is a partially cross-sectioned top plan view of a binocularaccording to another modification of the invention, FIG. 13 being across-sectional view taken along the line XIII--XIII in FIG. 14;

FIG. 14 is a rear elevational view of the binocular illustrated in FIG.13;

FIG. 15 is a partially broken-away top plan view of the binocularillustrated in FIG. 13, showing a focusing mechanism;

FIG. 16 is a fragmentary cross-sectional view of one of a pair ofobjective lens-barrels shown in FIGS. 13 through 15;

FIG. 17 is an enlarged fragmentary cross-sectional view showing asupport plate and one of a pair of bearing elements incorporated in thebinocular illustrated in FIG. 13 through 16;

FIG. 18 is a schematic view of an interlocking mechanism incorporated inthe binocular illustrated in FIGS. 13 through 17;

FIG. 19 is a view similar to FIG. 18, but showing a variation of theinterlocking mechanism;

FIG. 20 is a partially cross-sectioned top plan view of a binocularaccording to still another modification of the invention, FIG. 20 beinga cross-sectional view taken along the line XX--XX in FIG. 21;

FIG. 21 is a rear elevational view of the binocular as viewed from theside of a pair of eyepiece lens-barrels illustrated in FIG. 20;

FIG. 22 is a partially broken-away top plan view of the binocularillustrated in FIG. 20, showing a focusing mechanism;

FIG. 23 is a fragmentary cross-sectional view of one of a pair ofobjective lens-barrels shown in FIG. 20 through 22;

FIG. 24 is an enlarged fragmentary cross-sectional view showing asupport plate and one of a pair of bearing elements incorporated in thebinocular illustrated in FIG. 20;

FIG. 25 is a view similar to FIG. 24, but showing a variation of thebearing element;

FIG. 26 is a view similar to FIG. 24, but showing another variation ofthe bearing element;

FIG. 27 is a view similar to FIG. 24, but showing still anothervariation of the bearing element;

FIG. 28 is a view similar to FIG. 24, but showing another variation ofthe bearing element;

FIG. 29 is a view similar to FIG. 24, but showing still anothervariation of the bearing element;

FIG. 30 is a fragmentary cross-sectional view of an improvedmodification of the binocular illustrated in FIGS. 20 through 24;

FIG. 31 is a partially cross-sectioned top plan view taken along lineXXXI--XXXI FIG. 32 of a binocular according to another modification ofthe invention;

FIG. 32 is a rear elevational view of the binocular as viewed from theside of a pair of eyepiece lens-barrels illustrated in FIG. 31;

FIG. 33 is a partially broken-away top plan view of the binocularillustrated in FIG. 31, showing a focusing mechanism;

FIG. 34 is a fragmentary cross-sectional view of one of the pair ofobjective lens-barrels shown in FIGS. 31 through 33;

FIG. 35 is an enlarge fragmentary cross-sectional view of the binocularillustrated in FIGS. 31 through 33, showing a support plate and one of apair of bearing elements;

FIG. 36 is a partially cross-sectioned top plan view taken along lineXXXVI--XXXVI in FIG. 37 of a binocular according still anothermodification of the invention;

FIG. 37 is a rear elevational view of the binocular as viewed from theside of a pair of eyepiece lens-barrels illustrate in FIG. 36;

FIG. 38 is a fragmentary cross-sectional view showing one of the pair ofobjective lens-barrels illustrated in FIGS. 36 and 37;

FIG. 39 is a view similar to FIG. 36, but showing another modificationof the invention;

FIG. 40 is a partially cross-sectioned top plan view taken along lineXL--XL in FIG. 41 of a binocular according to still another modificationof the invention;

FIG. 41 is a rear elevational view of the binocular illustrated in FIG.40;

FIG. 42 is a partially broken-away top plan view of the binocularillustrated in FIGS. 40 and 41, showing a focusing mechanism;

FIG. 43 is an enlarged fragmentary cross-sectional view of a supportplate and one of a pair of bearing elements incorporated in thebinocular illustrated in FIGS. 40 through 42;

FIG. 44 is a view similar to FIG. 42, but showing a variation of thefocusing mechanism;

FIG. 45 is a cross-sectional view taken along the line XLV--XLV in FIG.44;

FIG. 46 is a view similar to FIG. 45, but showing another variation ofthe focusing mechanism;

FIG. 47 is a view similar to FIG. 45, but showing still anothervariation of the focusing mechanism;

FIG. 48 is a fragmentary cross-sectional view of an improvedmodification of the binocular illustrated in FIGS. 40 through 45;

FIG. 49 is a partially cross-sectioned top plan view of a binocularaccording to still another modification of the invention, FIG. 49 beinga cross-sectional view taken along the line XLIX--XLIX in FIG. 50;

FIG. 50 is a rear elevational view of the binocular as viewed from theside of a pair of eyepiece lens-barrels illustrated in FIG. 49;

FIG. 51 is a partially broken-away top plan view of the binocularillustrated in FIGS. 49 and 50, showing a focusing mechanism;

FIG. 52 is a fragmentary cross-sectional view of one of the pair ofobjective lens-barrels shown in FIGS. 49 through 51;

FIG. 53 is an enlarged fragmentary cross-sectional view of a supportplate and one of a pair of bearing elements incorporated in thebinocular illustrated in FIGS. 49 through 52;

FIG. 54 is a cross-sectional view taken along a longitudinal center lineof the binocular illustrated in FIGS. 49 through 53;

FIG. 55 is a partially cross-sectioned top plan view of a binocularaccording to still another modification of the invention, the binocularcomprising a single objective lens-barrel common to a pair of eyepiecelens-barrels;

FIG. 56 is a rear elevational view of the binocular as viewed from theside of the pair of eyepiece lens-barrels illustrated in FIG. 55,showing a magnifying lens unit;

FIG. 57 is a view similar to FIG. 56, but showing a variation of themagnifying lens unit illustrated in FIG. 55;

FIG. 58 is a partially cross-sectioned top plan view of a binocularaccording to another modification of the invention, which comprises azooming mechanism;

FIG. 59 is a diagrammatic fragmentary developed view of the zoomingmechanism illustrated in FIG. 58, showing the objective lens-barrel in atelescopic position;

FIG. 60 is a view similar to FIG. 59, but showing the objectivelens-barrel in a wide-angle position; and

FIG. 61 is a rear elevational view of an improved modification of thebinocular illustrated in 58, which comprises an interlocking mechanism.

DESCRIPTION OF THE EMBODIMENT

Referring first to FIGS. 4 through 8, there is shown a binocularembodying the invention, which comprises a binocular body 101 and a pairof left- and right-hand lens-barrel units 106 and 107 mounted to thebody 101 for angular movement relative thereto independently of eachother. The left-hand lens-barrel unit 106 is composed of an objectivelens-barrel 106b, an eyepiece lens-barrel 106d and an image-erectingchamber section 106c arranged between them. The objective lens-barrel106b is fixedly connected to the image-erecting chamber section 106c.The objective lens barrel 106b has incorporated therein an objectivelens system 121a, while the eyepiece lens barrel 106d has incorporatedtherein an eyepiece lens system 122a. The image-erecting chamber section106c has incorporated therein a Porro mirror or a Porro prism systemlike that illustrated in, for example, FIG. 13 subsequently to bedescribed. The prism system within the image-erecting chamber section106c serves to optically connect an optical axis 1 of the objective lenssystem 121a to an optical axis of the eyepiece lens system 122a. Theright-hand lens-barrel unit 107 is constructed in a manner similar tothat of the left-hand lens-barrel unit 106 described above. The pair oflens-barrel units 106 and 107 are mounted to the body 101 for angularmovement relative thereto about the respective optical axes 1 and 1' ofthe objective lens systems 121a and 121b subsequently to be described.

As clearly shown in FIG. 8, the body 101 is formed therein with a pairof retaining bores 102 and 103 having their respective axes k and k'which extend parallel to each other. Each of the retaining bores 102 and103 has one end portion thereof adjacent a corresponding one of the pairof eyepiece lens-barrels 106c and 107c. A peripheral wall of the endportion of the retaining bore 32, 33 is cut out partially to form a pairof cut-out edges 101a and 101b. Although only the retaining bore 102 isshown in FIG. 4, the other end portion of the retaining bore 102 has aninner peripheral surface 102a which is so tapered as to converge. Theretaining bore 103 is also provided with a tapered inner peripheralsurface portion similar to the tapered surface 102. The binocular body101 has an intermediate wall 101c extending between upper and lowersurfaces 101d and 101e of the body 101. The intermediate wall 101c islocated between the pair of retaining bores 102 and 103 and extendsalong their respective axes k and k'. The intermediate wall 101c has anend face formed therein with two upper and lower pairs of threaded bores104a and 104b and 104c and 104d for a support plate 111 of a supportmechanism, and two upper and lower threaded bores 105a and 105b and 105cand 105d for a cover plate 116, subsequently to be described.

As will be seen from FIGS. 4 and 6, the objective lens-barrels 106b and107b of the respective lens-barrel units 106 and 107 are fittedrespectively in the retaining bores 32 and 33 in such a manner that theaxes k and k' of the respective objective lens-barrels 106b and 107b arecoincident respectively with the optical axes 1 and 1' of the respectiveobjective lens systems 121a and 121b. As shown in FIG. 4, the objectivelens-barrel 106b has one end portion thereof remote from theimage-erecting chamber section 106c. The end portion of the objectivelens-barrel 106b has an outer peripheral surface 106a which is taperedin complementary relation to the tapered inner peripheral surface 102aof the end portion of the retaining bore 102. The tapered outerperipheral surface 106a of the objective lens barrel 106b is in slidingcontact with the tapered inner peripheral surface 102a of the retainingbore 102. It is needless to say that the right-hand objectivelens-barrel 107b is also provided with a tapered outer peripheralsurface portion similar to the tapered surface 106a. In this manner, thepair of lens-barrel units 106 and 107 are mounted to the binocular body101 for angular movement about the respective optical axes 1 and 1' ofthe objective lens systems 121a and 121b. Moreover, sliding contactbetween the tapered surfaces 102a and 106a ensures smooth angularmovement of the lens-barrel units 106 and 107 relative to the binocularbody 101.

The lens-barrel units 106 and 107 and the support mechanism thereforwill next be described in more detail. The lens-barrel units 106 and 107are similar in construction to each other, except that they aresymmetrical in configuration to each other, and only the lens-barrelunit 106 will therefore be described.

As shown in FIG. 8, the lens-barrel unit 106 is composed of theobjective lens-barrel 106b, the image-erecting chamber section 106c andthe eyepiece lens-barrel 106d. The lens-barrel unit 106 is mounted tothe body 101 such that the axis k of the objective lens-barrel 106b iscoincident with the optical axis 1 of the objective lens system 121a andin such a manner that the lens-barrel unit 106 is movable angularlyabout the optical axis 1 of the objective lens system 121a. Theimage-erecting chamber section 106c has an end face remote from theobjective lens-barrel 106b. The end face of the image-erecting chambersection 106c is formed with a conical recess 108 at a location on anextension line of the optical axis 1. On the other hand, the supportplate 111 is formed therein with a receiving bore 110a which cooperateswith the recess 108 to receive therein a bearing element or a ball 109in a rolling manner. The support plate 111 is also provided with twoupper and lower pairs of through bores 112a and 112b and 112c and 112dwhich correspond respective to the threaded bores 104a, 104b, 104c and104d. The support plate 111 is mounted to the end face of theintermediate wall 101c of the body 101 by means of screws 113, with theball 109 received in and clamped between the recess 108 and thereceiving bore 110a. In this manner, the lens-barrel unit 106 issupported by the body 101 and the support plate 111 for angular movementrelative to the body 101 about the optical axis 1 of the objective lenssystem 121a.

As shown in FIGS. 7 and 8, an arcuate projection 114 is provided on theouter periphery of the objective lens-barrel 106b and extends along theend face of the image-erecting chamber section 106c remote from theeyepiece lens-barrel 106d. The arcuate projection 114 has its oppositeends capable of being abutted respectively against the cut-out edges101a and 101b which serve to regulate a range of angular movement of thelens-barrel unit 106 relative to the body 101 about the optical axis 1of the objective lens system 121a.

As shown in FIGS. 4 and 8, the eyepiece lens-barrel 106d is covered withan eyepiece cover 115.

The lens-barrel unit 107 is constructed in a manner similar to thelens-barrel unit 106 described above. That is, a receiving bore 110b inthe support plate 111 is employed to partially receive a ball so as tosupport the lens-barrel unit 107 for angular movement relative to thebody 101 about the optical axis 1' of the objective lens system 121b.

As shown in FIGS. 4 and 5, a rear cover plate 116 is mounted to the endface of the intermediate wall 101c of the body 101 by means of screws117 screwed into the threaded bores 105a through 105d, in order toconceal the support plate 111. Moreover, as shown in FIGS. 4 and 6, afront cover 118 is attached to an end of the body 101 adjacent theobjective lens-barrels 106b and 107b.

A lever 119 is mounted on the upper surface 101d of the body 101 forangular movement relative thereto about an axis extendingperpendicularly to the optical axes 1 and 1' of the respective objectivelens systems 121a and 121b. The lever 119 is operatively connected to apair of inner tubular members of the respective objective lens-barrels106b and 107b. The inner tubular members have incorporated therein theirrespective objective lens systems 121a and 121b, and are movablerelative to respective outer tubular members of the objectivelens-barrels 106b and 107b along the respective optical axes 1 and 1' ofthe optical lens systems 121a and 121b in a manner similar to thatsubsequently to be described with reference, for example, to FIG. 13.Angular movement of the lever 119 causes the inner tubular members tomove relative to the respective outer tubular members, thereby adjustingthe focus of the binocular.

In the binocular constructed as described above, when it is desired toadjust the distance between the pair of eyepiece lens-barrels 106d and107d to match the distance between the observer's eyes, the eyepiecelens-barrels 106d and 107d are moved toward and away from each otherangularly about the respective pivotal axes which are coincidentrespectively with the optical axes 1 and 1' of the objective lenssystems 121a and 121b. The optical axes 1 and 1' are always maintainedstationary during angular movement of the eyepiece lens-barrels 106d and107d, and the distance between the optical axes 1 and 1' is maintainedunchanged. This makes it easy to regulate the pair of optical axes 1 and1' with a high accuracy during assembling of the binocular. Moreover, itis possible to incorporate a flat plate-like polarizing filter or thelike in the binocular in a common relation to the pair of lens-barrelunits 106 and 107. Moreover, since the binocular body 101 is maintainedstationary during adjustment of the distance between the intereyepiecedistance, the binocular body 101 can be provided in its lower surface101e with an attaching bore for a tripod.

FIGS. 9 through 12 show a modified form of the binocular according tothe invention. In these figures, components and parts like or similar tothose illustrated in FIGS. 4 through 8 are designated by the same orlike reference numerals, and the description of such like or similarcomponents and parts will therefore be omitted to avoid repetition.

The binocular illustrated in FIGS. 9 through 12 is different from thebinocular shown in FIGS. 4 through 8 in that an interlocking mechanismis arranged between the pair of lens-barrel units 106 and 107 forinterlocking them with each other in such a manner as to enable the pairof eyepiece lens-barrels 106d and 107d to be moved angularly in theirrespective directions opposite to each other respectively about theoptical axes 1 and 1' of the respective objective lens systems 121a and121b.

Specifically, the interlocking mechanism comprises a drive shaft 168formed with a worm 167. The drive shaft 168 is rotatably mounted to theintermediate wall 101c of the binocular body 101 and has an axisextending perpendicularly to the optical axes 1 and 1' of the respectiveobjective lens systems 121a and 121b. The drive shaft 168 has an upperend portion thereof which projects from the upper surface 101d of theintermediate wall 101c. An operating member 169 is fixedly mounted tothe projecting end portion of the drive shaft 168. As shown in FIGS. 9and 12, the operating member 169 is provided on its upper face with anindex 170, while graduations 171 are provided on the upper surface 101dof the body 101. The arrangement is such that angular movement of theoperating lever 169 causes the drive shaft 168 to be moved angularlyabout its axis in the same direction and by the same amount of angularmovement as the operating lever 169. The position of the index 170relative to the graduations 171 makes it possible to read the directionof the angular movement and the amount of angular movement.

The interlocking mechanism further includes a pair of arcuate groups ofgear teeth 181a and 181b formed respectively on the outer peripheries ofthe pair of image-erecting chamber sections 106c and 107c. The gearteeth 181a and 181b are in mesh with the worm 167. The arrangement issuch that the pair of lens-barrel units 106 and 107 are angularly movedin interlocked relation to each other about the respective optical axes1 and 1' of the objective lens systems 121a and 121b in the clockwise orcounterclockwise direction as viewed in FIG. 10, in accordance with thedirection and the amount of angular movement of the operating lever 169.

As described above, the binocular illustrated in FIGS. 9 through 12 isadvantageous in that operation of the operating lever 169 makes it easyto adjust the distance between the pair of eyepiece lens barrels 106dand 107d, in addition to the same advantages as the binocularillustrated in FIGS. 4 through 8.

FIGS. 13 through 18 show another modified form of the binocularaccording to the invention, which comprises a binocular body 231 and apair of left- and right-hand lens-barrel units 232 and 247 mounted tothe body 231 for angular movement relative thereto subsequently to bedescribed in detail. The left-hand lens-barrel unit 232 is composed ofan objective lens-barrel 232a, an eyepiece lens-barrel 232b and animage-erecting chamber section 236. The image-erecting chamber section236 has an elliptical outer casing and is arranged between the objectivelens-barrel 232a and the eyepiece lens-barrel 232b. The objectivelens-barrel 232a is cylindrical in shape and is composed of an outertubular member 232a₁ and an inner tubular member 232a₂. The outertubular member 231a₁ is fixedly connected to the outer casing of theimage-erecting chamber section 236 and, in case of the illustratedmodification, is formed in integral relation to the outer casing of theimage-erecting chamber section 236. The inner tubular member 232a₂ hasincorporated therein an objective lens system 233. The inner tubularmember 232a₂ is accommodated within the outer tubular member 232a₁ inconcentric relation thereto so as to prevent angular movement relativeto the outer tubular member 232a₁ about an axis of the inner tubularmember 232a₂, but allowing reciprocal movement relative to the outertubular member 232a₁ along the axis of the inner tubular member 232a₂.

The binocular body 231 is formed therein with a pair of retaining bores231a and 281a (see FIG. 15). The objective lens-barrel 232a isaccommodated in the retaining bore 231a such that the outer tubularmember 232a₁ of the objective lens-barrel 232a is angularly movablerelatively to the binocular body 231 about the optical axis 1 of theobjective lens system 233. The binocular body 231 is provided with anannular flange 231b at an end of the retaining bore 231a remote from theimage-erecting chamber section 236. The outer tubular member 232a₁ has aforward end remote from the image-erecting chamber section 236, whichabuts against the annular flange 231b.

The inner tubular member 232a₂ having incorporated therein the objectivelens system 233 is received within the outer tubular member 232a₁ forsliding movement relative thereto along the optical axis 1 of theobjective lens system 233. The inner tubular member 232a₂ is formed, inan outer periphery thereof, with an elongated groove 234b extendingalong the optical axis 1 of the objective lens system 233. A pin 235 ismounted to the outer tubular member 232a₁ and has a forward end portionwhich is received in the elongated groove 234b to prevent the innertubular member 232a₂ from being angularly moved relatively to the outertubular member 232a₁ about the optical axis 1 of the objective lenssystem 233. The inner tubular member 232a₂ is designed to be movedreciprocatively along the optical axis 1 of the objective lens system233 by a focusing mechanism subsequently to be described.

The image-erecting chamber section 236 has incorporated therein a pairof prism systems 237 and 238 for erecting an image and for opticallyconnecting the optical axis 1 of the objective lens system 233 to anoptical axis of an eyepiece lens system 239 incorporated in the eyepiecelens barrel 232b. The image-erecting chamber section 236 has one endwall 261 to which the outer tubular member 232a₁ is fixedly connected.The one end wall 261 is formed therein with a bore 263 aligned with theoptical axis 1 of the objective lens system 233. A bore 264 formed inthe other end wall 262 of the image-erecting chamber section 236 isaligned with the optical axis of the eyepiece lens system 239.

The binocular body 231 is provided with a substantially hollowintermediate wall structure 266 arranged between the pair of retainingbores 231a and 281a. The intermediate wall structure 266 has a portionthereof projecting from a plane including end faces of the respectiveretaining bores 231a and 281a, toward the eyepiece lens barrels 232b and247b. A support plate 241 formed of elastic material is mounted to anend face of the projecting portion of the intermediate wall structure266 by means of screws 252. A rear cover 240 is also mounted to the endface of the projecting portion of the intermediate wall structure 266 soas to cover the support plate 241.

The support plate 241 is designed to urge the outer tubular member 232a₁of the objective lens-barrel 232a through the image-erecting chambersection 236 so that the forward end of the outer tubular member 232a₁ isabutted against the annular flange 231b on the binocular body 231.Specifically, as shown in FIG. 17, a conical recess 236a is formed inthe face of the end wall 262 of the image-erecting chamber section 236at a location on an extension line of the optical axis 1 of theobjective lens system 233. A bearing element or a ball 242 is partiallyreceived in the recess 236a and is resiliently or elastically urgedagainst the recess 236a by the support plate 241.

The focusing mechanism comprises an operating roller 243 for moving theinner tubular member 232a₂ relatively to the outer tubular member 232a₁along the optical axis 1 of the objective lens system 233. As shown inFIG. 15, the operating roller 243 is composed of a roller body 243a anda threaded shaft 244 having a pair of shaft sections 243b and 243bprojecting respectively from the opposite end faces of the roller body243a. The shaft sections 243b and 243b of the operating roller 243 arerotatably supported by the binocular body 231. A threaded bore 243c isformed in the operating roller 243 and extends through the roller body243a and the pair of shaft sections 243b and 243b. The threaded shaft244 is threadedly engaged with the threaded bore 243c in concentricrelation to the operating roller 243 in such a manner that angularmovement of the operating roller 243 about its axis causes the threadedshaft 244 to be reciprocally moved relatively to the operating roller243 along the axis thereof.

A movable block member 245 is mounted to an end portion of the threadedshaft 244 remote from the operating roller 243 so that it is preventedfrom angular movement relative to the threaded shaft 244 about the axisthereof. A pair of interlocking arms 246a and 246b have their respectiveone ends fixedly mounted to the movable block member 245. Theinterlocking arm 246a extends laterally through an opening 231a₁ formedin the wall of the retaining bore 231a and through an opening 232a₁₁formed in the outer tubular member 232a₁ of the objective lens-barrel232. The interlocking arm 246a has a forward end which is received in anarcuate groove 232a₂₁ formed in the outer periphery of the inner tubularmember 232a₂ of the objective lens-barrel 232a.

As shown in FIG. 16, the movable block member 245 is provided with aprojection 245a projecting from the end of the movable block member 245adjacent the operating roller 234, in relation perpendicular to the axisof the threaded shaft 244. The projection 245a has a forward end thereofwhich is fitted in between a pair of guide projections 231c and 231dformed on the intermediate wall structure 266 of the binocular body 231in such a manner that the projection 245a is movable along theprojections 231c and 231d while being guided thereby.

The above-mentioned opening 232a₁₁ is rectangular in shape and is sodetermined in size as to permit the interlocking arm 246a to be movedreciprocatively along the axis of the threaded shaft 244, i.e., alongthe optical axis 1 of the objective lens system 233, and as to permitthe objective lens-barrel 232a to be moved angularly about the opticalaxis 1 of the objective lens system 233. The opening 231a₁ is formed ina manner similar to the opening 232a₁₁.

Although only the left-hand lens-barrel unit 232 has been described, theright-hand lens-barrel unit 247 is similar in construction to theleft-hand lens-barrel unit 232. That is to say, the right-handlens-barrel unit 247 is composed of an objective lens-barrel 247a, aneyepiece lens-barrel 247b and an image-erecting chamber section 248. Thedetailed description of the right-hand lens-barrel unit 247 will beomitted to avoid repetition.

The binocular illustrated in FIGS. 13 through 18 comprises aninterlocking mechanism arranged between the pair of image-erectingchamber sections 236 and 248 for interlocking them with each other insuch a manner that the pair of eyepiece lens-barrels 232b and 247b aremovable angularly in their respective directions opposite to each otherrespectively about the optical axes 1 and 1' of the objective lenssystems 233 and 271 incorporated respectively in the objectivelens-barrels 232a and 247a.

As shown in FIGS. 14 and 18, the interlocking mechanism is composed ofan elongated link 250 having a longitudinal axis which extends at anangle with respect to a line connecting the optical axes 1 and 1' of therespective objective lens systems 233 and 271. The elongated link 250has one end thereof which is pivotally connected to the face of the endwall 262 of the image-erecting chamber section 236 by means of a pivot249a. The other end of the elongated link 250 is likewise connectedpivotally to the face of the end wall 291 of the image-erecting chambersection 248 by means of a pivot 249b. A rear cover 240 is mounted to theend face of the intermediate wall structure 266 of the binocular body231 to cover the elongated link 250.

In the binocular illustrated in FIGS. 13 through 18, when it is desiredto adjust the distance between the eyepiece lens-barrels 232b and 247bto match the distance between the observer's eyes, one of the pair oflens-barrel units 232 and 247, for example, the lens-barrel unit 232 isangularly moved relatively to the binocular body 231 about the opticalaxis 1 of the objective lens system 233 and the extension line of theoptical axis 1 passing through the ball 242. The angular movement of thelens-barrel unit 232 is transmitted to the other lens-barrel unit 247 bythe longitudinal link 250, thereby angularly moving the lens-barrel unit247 about the optical axis 1' of the optical lens system 271 in thedirection opposite to the angular movement direction of the lens-barrelunit 232, as indicated by the double-dotted lines in FIG. 18. In thismanner, the intereyepiece distance can be adjusted to match the distancebetween the observer's eyes. During the adjustment of the intereyepiecedistance, the opening 232a₁₁ in the outer tubular member 232a₁ serves asa relief opening, and the arcuate groove 232a₂₁ in the inner tubularmember 232a₂ serves as a relief groove. Accordingly, no force is exertedupon the interlocking arm 246a. The same is applicable to the right-handlens-barrel unit 247.

When it is desired to adjust the focus of the binocular, the operatingroller 243 is angularly moved about the axis of the threaded shaft 244.Specifically, angular movement of the operating roller 243 causes thethreaded shaft 244 to be moved along its axis to move the interlockingarms 246a and 246b together with the threaded shaft 244. During angularmovement of the operating roller 243, the threaded shaft 244 isprevented from being angularly moved about its axis by the movable blockmember 245 which is fitted in the recess defined between the pair ofguide projections 231c and 231d. Further, since the interlocking arm246a is moved within the range of the openings 231a₁ and 232a₁₁, noforce is exerted upon the outer tubular member 232a₁ of the objectivelens-barrel 232a.

The movement of the interlocking arm 246a along the axis of the threadedshaft 244 causes the inner tubular member 232a₂ to be moved relativelyto the outer tubular member 232a₁ along the optical axis 1 of theobjective lens system 233, thereby adjusting the focus of the left-handlens-barrel 232. Likewise, the inner tubular member of the objectivelens-barrel 247a of the right-hand lens-barrel unit 247 is moved alongthe optical axis 1' of the objective lens system 271 relatively to theouter tubular member of the objective lens-barrel 247a. Thus, the focusof the right-hand lens-barrel unit 247 is adjusted.

FIG. 19 shows a modified form of the interlocking mechanism incorporatedin the binocular illustrated in FIGS. 13 through 18. The interlockingmechanism shown in FIG. 19 is composed of a pair of toothed plates 251aand 251b which are fixedly mounted respectively to the outer peripheriesof the respective image-erecting chamber sections 236 and 248. Thetoothed plates 251a and 251b are mounted respectively to theimage-erecting chamber sections 236 and 248 at respective locationsadjacent the end walls 261 and 291 of the respective age-erectingchamber sections 236 and 248, such that the toothed plates 251a and 251bare covered by the rear cover 240. The pair of toothed plates 251a and251b are in mesh with each other so that the pair of eyepiecelens-barrels 232b and 247b are interlocked with each other.

When the binocular illustrated in FIGS. 13 through 18 or FIG. 19 isassembled, the left- and right-hand lens-barrel units 232 and 247 arefirst mounted to the binocular body 231. Subsequently, the focusingmechanism composed of the operating roller 243, the movable block member245 and the like is assembled into the binocular body 231 from above.Thereafter, a body cover member 231e is mounted to the upper surface ofthe body 231 so as to cover the focusing mechanism, with the operatingroller 243 exposed partially.

As described above, the arrangement of the binocular illustrated inFIGS. 13 through 18 or FIG. 19 is such that the pair of eyepiecelens-barrels 232b and 247b are angularly moved, in interlocked relationto each other, relative to the binocular body 231 respectively about theoptical axes 1 and 1' of the respective objective lens systems 233 and271 incorporated in the objective lens-barrels 232a and 247a, in orderto adjust the intereyepiece distance to match the distance between theobserver's eyes. With such arrangement, the intereyepiece-distanceadjusting mechanism and the focusing mechanism can be separated fromeach other, making it possible to simplify the construction of each ofthem. Further, the number of component parts of intereyepiece-distanceadjusting mechanism and the focusing mechanism can be reduced, therebyfacilitating assembly of the binocular. Moreover, the interlockedrelationship between the pair of lens-barrel units 232 and 247 enhancesthe ease of adjustment of the intereyepiece distance, and also improvesthe outer configuration and appearance of the binocular in use.

FIGS. 20 through 24 show a modified form of the binocular illustrated inFIGS. 13 through 18. In FIGS. 20 through 24, components and parts likeor similar to those illustrated in FIGS. 13 through 18 are designated bythe same or like reference numerals, and the description of such like orsimilar components and parts will therefore be omitted to avoidrepetition.

The binocular illustrated in FIGS. 20 through 24 is different from thebinocular shown in FIGS. 13 through 18 in that the interlockingmechanism is not arranged between the pair of lens-barrel units 232 and247, but the pair of the lens-barrel units 232 and 247 are angularlymovable independently of each other about the respective optical axes 1and 1' of the optical lens systems 233 and 271. Thus, it is possible forthe binocular shown in FIGS. 20 through 24 to simplify the constructionand to reduce the manufacturing cost.

FIGS. 25 through 29 show various modified forms of the support mechanismfor the pair of lens-barrel units 232 and 247 illustrated in FIGS. 13through 18 or FIGS. 20 through 24, and correspond to FIG. 17 or FIG. 24.It is to be understood that, although only the image-erecting chambersection 236 of the left-hand lens-barrel unit 232 is shownfragmentarily, the same is applicable to the image-erecting chambersection 248 of the right-hand lens-barrel unit 247.

The support mechanism shown in FIG. 25 comprises a bearing element whichis composed of a projecting pin 289a mounted to the elastic supportplate 241. The projecting pin 289a has a generally pointed forward endthereof received in the conical recess 236a formed in the end plate 262of the image-erecting chamber section 236.

The support mechanism shown in FIG. 26 comprises a bearing element whichis composed of a projecting pin 289b mounted to the elastic supportplate 241. The projecting pin 289a has a rounded forward end thereofreceived in the conical recess 236a formed in the end wall 262 of theimage-erecting chamber section 236.

The support mechanism shown in FIG. 27 comprises a bearing element whichis composed of a projecting pin 289c threadedly engaged with the elasticsupport plate 241. The projecting pin 389c has a generally pointedforward end thereof received in the conical recess 236a formed in theend wall 262 of the image-erecting chamber section 236.

The support mechanism shown in FIG. 28 comprises a bearing element whichis composed of a projecting pin 289d threadedly engaged with the elasticsupport plate 241. The projecting pin 289d has a rounded forward endthereof received in the conical recess 236a formed in the end wall 262of the image-erecting chamber section 236.

The support mechanism shown in FIG. 29 comprises a bearing element whichis composed of a threaded member 289e threadedly engaged with theelastic support plate 241, and the ball 242 arranged between a forwardend of the threaded member 289e and the conical recess 236a formed inthe end wall 262 of the image-erecting chamber section 236.

FIG. 30 shows a modified form of the binocular illustrated in FIGS. 13through 18 or FIGS. 20 through 24. In the modified form shown in FIG.30, the retaining bore 331a has an end portion 331c remote from theimage-erecting chamber section 336. The end portion 331c of theretaining bore 331a is tapered so as to converge. The outer tubularmember 332a₁ of the objective lens-barrel 332a has an end portion 332cremote from the image-erecting chamber section 336. The end portion 332cof the outer tubular member 332a₁ is tapered in complementary relationto the tapered end portion 331c of the retaining bore 331a. An elasticsupport plate corresponding to the elastic support plate 241 shown inFIG. 17 urges the objective lens-barrel 332a through the image-erectingchamber section 336 so that the tapered end portion 332c of the outertubular member 332a₁ is in sliding contact with the tapered end portion331c of the retaining bore 331a. The right-hand lens-barrel unit,although not shown, is constructed in a similar manner.

The arrangement of the binocular shown in FIG. 30 is such that taperedend portion 332c of the outer tubular member 332a₁ of the objectivelens-barrel 332a is slidably abutted against the tapered end portion331c of the retaining bore 331a in the binocular body 331, and theimage-erecting chamber section 336 is urged and supported by the supportplate. With such arrangement, any mechanical play of the lens-barrelunit 332 can effectively be absorbed, and adequate frictional resistancecan be applied to the angular movement of the objective lens-barrel332a.

FIGS. 31 through 35 show a modified form of the binocular illustrated inFIGS. 13 through 18. In FIGS. 31 through 35, components and parts likeor similar to those illustrated in FIGS. 13 through 18 are designated bythe same or like reference numerals, and the description of such like orsimilar components and parts will therefore be omitted to avoidrepetition.

The binocular illustrated in FIGS. 31 through 35 is different from thebinocular shown in FIGS. 13 through 18 in that, in each of the pair oflens-barrel units, the objective lens-barrel is formed separately fromthe image-erecting chamber section.

Specifically, as shown in FIG. 31, the objective lens-barrel 432a isformed separately from the image-erecting chamber section 436. Theobjective lens-barrel 432a is accommodated in the retaining bore 431a soas to prevent angular movement relative to the binocular body 431 aboutthe optical axis 1 of the objective lens system 433, but allowingreciprocal movement relative to the binocular body 431 along the opticalaxis 1 of the objective lens system 433.

The binocular body 431 is formed therein with a bore 401 so tapered asto diverge away from the objective lens-barrel 436. The tapered bore 401in the binocular body 431 is aligned with the optical axis 1 of theobjective lens system 433. The image-erecting chamber section 436 isprovided with a hollow projection 402 which is aligned with the opticalaxis 1 of the objective lens system 433. The hollow projection 402 hasan outer periphery which is tapered in complementary relation to thetapered bore 401 in the binocular body 431. The tapered hollowprojection 402 is fitted in the tapered bore 401 in the binocular body431 in such a manner that the outer periphery of the hollow projection402 is in sliding contact with the tapered bore 401 in the binocularbody 431.

As clearly shown in FIG. 35, a bearing element or a projecting pin 442is threadedly engaged with the support plate 441 formed of elasticmaterial. The projecting pin 442 has a generally pointed forward endthereof received in the conical recess 436a formed in the end wall 462of the image-erecting chamber section 436. The projecting pin 442 isarranged on the extension line of the optical axis 1 of the objectivelens system 433. The support plate 441 resiliently urges theimage-erecting chamber section 436 toward the objective lens-barrel 432aso that the outer periphery of the hollow projection 402 is abuttedagainst the tapered bore 401 in the binocular body 431. Turningadjustment of the projecting pin 442 enables the abutting pressure ofthe tapered hollow projection 402 against the tapered bore 401 to bevaried, thereby making it possible to eliminate any mechanical play inangular movement of the image-erecting chamber section 436.

In the focusing mechanism of the binocular illustrated in FIGS. 31through 35, the interlocking arm 246a extends laterally through theopening 431a₁ formed in the wall of the retaining bore 431a, and theforward end of the interlocking arm 246a is received in a recess 432a₂formed in the outer periphery of the objective lens-barrel 432a. Angularmovement of the operating roller 243 causes the threaded shaft 244 to bereciprocatively moved together with the interlocking arm 246a along theaxis of the threaded shaft 244, thereby reciprocally moving theobjective lens-barrel 432a relative to the binocular body 431 along theoptical axis 1 of the objective lens system 433, but preventing angularmovement of the objective lens-barrel 432a relative to the binocularbody 431 about the optical axis 1 of the objective lens system 433.

Only the left-hand lens-barrel unit 432 of the binocular illustrated inFIGS. 31 through 35 has been described. However, the same technicalconcept is applied to the right-hand lens barrel unit 447. That is, theright-hand lens-barrel unit 447 is composed of an objective lens-barrel447a, an image-erecting chamber section 448 and an eyepiece lens-barrel447b, which correspond respectively to the objective lens-barrel 432a,the image-erecting chamber section 436 and the eyepiece lens-barrel432b.

As shown in FIG. 32, the interlocking mechanism similar to thatillustrated in FIG. 19 is incorporated in the binocular illustrated inFIGS. 31 through 35. That is, the pair of toothed plates 251a and 251bare fixedly mounted respectively to the outer peripheries of therespective image-erecting chamber sections 436 and 448. The toothedplates 251a and 251b are mounted respectively to the image-erectingchamber sections 436 and 448 at respective locations adjacent the endwalls 462 and 491 of the respective image-erecting chamber sections 436and 448, such that the toothed plates 251a and 251b are covered by therear cover 240. The pair of toothed plates 251a and 251b are in meshwith each other so that the pair of eyepiece lens-barrels 432b and 447bare interlocked with each other.

FIGS. 36 through 38 shows a modified form of the binocular illustratedin FIGS. 31 through 35. In FIGS. 36 through 38, components and partslike or similar to those illustrated in FIGS. 31 through 35 aredesignated by the same or like reference numerals, and the descriptionof such like or similar components and parts will therefore be omittedto avoid repetition.

The binocular illustrated in FIGS. 36 through 38 is different from thebinocular shown in FIGS. 31 through 35 mainly in that the interlockingmechanism is not arranged between the pair of lens-barrel units 532 and547, but the pair of the lens-barrel units 532 and 547 are angularlymovable independently of each other about the respective optical axes 1and 1' of the optical lens systems 533 and 571, and in that theobjective lens-barrel 532 is accommodated in the retaining bore 531a sothat angular movement is prevented relative to the binocular body 531about the optical axis 1 by means of a pin 505 mounted to the wall ofthe retaining bore 531a in the binocular body 531.

As shown in FIG. 36, the image-erecting chamber section 536 is providedwith a hollow projection 502 whose forward end projects from the taperedbore 501 in the binocular body 531 into the retaining bore 531a. Aretaining ring 506 such as, for example, a screw nut is arranged withinthe retaining bore 531a and is threadedly engaged with an outerperiphery of the forward end of the hollow projection 502, to preventthe hollow projection 502 from coming out of the tapered bore 501 in thebinocular body 531.

Only the left-hand lens-barrel unit 532 of the binocular illustrated inFIGS. 36 through 38 has been described. However, the same technicalconcept is applied to the right-hand lens barrel unit 547. That is, theright-hand lens-barrel unit 547 is composed of an objective lens-barrel547a, an image-erecting chamber section 548 and an eyepiece lens-barrel547b, which correspond respectively to the objective lens-barrel 532,the image-erecting chamber section 536 and the eyepiece lens-barrel532b.

FIG. 39 shows a modified form of the binocular illustrated in FIGS. 13through 18. In FIG. 39, components and parts like or similar to thoseillustrated in FIGS. 13 through 18 are designated by the same or likereference numerals, and the description of such like or similarcomponents and parts will therefore be omitted to avoid repetition.

The binocular illustrated in FIG. 39 is different from the binocularshown in FIGS. 13 through 18 in that the binocular has no interlockingmechanism, but comprises retaining means arranged between the binocularbody 231 and the outer tubular member 232a₁ of the objective lens-barrel232a for preventing the same from coming out of the retaining bore 231ain the binocular body 231. Specifically, an annular recess 231d isformed in the end face of the binocular body 231 remote from theimage-erecting chamber section 236. The retaining means is composed of aretaining ring 209 such as, for example, a screw nut which is receivedin the annular recess 231d and is threadedly engaged with an outerperiphery of the outer tubular member 232a₁.

Only the left-hand lens-barrel unit of the binocular illustrated in FIG.39 has been described. However, the same technical concept is applied tothe right-hand lens barrel unit 247.

FIGS. 40 through 43 shows another modified form of the binocularillustrated in FIGS. 13 through 18. In FIGS. 40 through 43, componentsand parts like or similar to those illustrated in FIGS. 13 through 18are designated by the same or like reference numerals, and thedescription of such like or similar components and parts will thereforebe omitted to avoid repetition.

The binocular illustrated in FIGS. 40 through 43 is different from thebinocular shown in FIGS. 13 through 18 in that the binocular has nointerlocking mechanism, but comprises thread means arranged between theinner tubular member 632a₂ and the outer tubular member 632a₁ forenabling the inner tubular member 632a₂ to be moved relatively to theouter tubular member 632a₁ along the optical axis 1 of the objectivelens system 633 when the inner tubular member 632a₂ is moved angularlyabout its own axis. Specifically, helicoid threads 611 are formed in theinner periphery of the outer tubular member 632a₁, while helicoidthreads 612 are formed in the outer periphery of the inner tubularmember 632a₂. The inner and outer tubular members 632a₂ and 632a₁ arethreadedly engaged with each other through the helicoid threads 611 and612.

The binocular illustrated in FIGS. 40 through 42 comprises a focusingmechanism. As best shown in FIG. 42, the focusing mechanism includes anoperating roller 643 which is mounted on a shaft 644 for angularmovement therewith about an axis of the shaft 644. A gear wheel 646 ismounted to the shaft 644 for angular movement therewith about the axisof the shaft 644. The gear wheel 646 has a peripheral portion whose partextends into the retaining bore 631a in the binocular body 631 throughan opening 631a₁ formed in the wall of the retaining bore 631a and anopening 632a₁₁ formed in the outer tubular member 632a₁. The gear wheel646 is in mesh with gear teeth 614 formed on the outer periphery of theinner tubular member 632a₂. The shaft 644 transmits angular movement ofthe operating roller 643 to the inner tubular member 632a₂ through thegear wheel 646, thereby angularly moving the inner tubular member 632a₂relatively to the outer tubular member 632a₁ about the optical axes 1 ofthe objective lens system 633. Because of the threaded engagementbetween the helicoid threads 611 and 612, the angular movement of theinner tubular member 632a₂ relative to the outer tubular member 632a₁causes the inner tubular member 632a₂ to be reciprocatively movedrelatively to the outer tubular member 632a₁ along the optical axis 1 ofthe objective lens system 633.

Only the left-hand lens-barrel unit 632 of the binocular illustrated inFIGS. 40 through 43 has been described. However, the same technicalconcept is applied to the right-hand lens barrel unit 647. That is, theright-hand lens-barrel unit 647 is composed of an objective lens-barrel647a, an image-erecting chamber section 648 and an eyepiece lens-barrel647b, which correspond respectively to the objective lens-barrel 632a,the image-erecting chamber section 636 and the eyepiece lens-barrel632b. It is noted that the helicoid threads 611 and 612 in the left-handlens-barrel 632 are opposite in direction to helical threads in theright-hand lens-barrel unit 647, because the inner tubular member of theright-hand objective lens-barrel 647a is angularly moved by the gearwheel 646 in the direction opposite to that of the inner tubular member632a₂ of the left-hand objective lens-barrel 632a.

FIGS. 44 and 45 show a modified form of the binocular illustrated inFIGS. 40 through 43. In FIGS. 44 and 45, components and parts like orsimilar to those illustrated in FIGS. 40 through 43 are designated bythe same or like reference numerals, and the description of such like orsimilar components and parts will therefore be omitted to avoidrepetition.

The binocular illustrated in FIGS. 44 and 45 is different from thebinocular shown in FIGS. 40 through 43 in the arrangement of thefocusing mechanism. That is, an operating knob 643a is mounted to thebinocular body 631 for reciprocal linear movement relative thereto alonga guide bore 618 in the wall of the binocular body 631 in a directionperpendicular to the optical axis 1 of the objective lens system. Anendless belt 619 extends between and runs around the inner tubularmember 632a₂ of the left-hand objective lens-barrel 632a and the innertubular member 672 of the right-hand objective lens-barrel 647a.Specifically, the endless belt 619 runs around the outer periphery of anend portion of the inner tubular member 632a₂ adjacent theimage-erecting chamber section 636. The endless belt 619 transmitsreciprocal linear movement of the operating knob 643a to the innertubular member 632a₂ to angularly move the inner tubular member 672about its axis relative to the outer tubular member 673.

In the binocular illustrated in FIGS. 44 and 45, the opening 631a₁₂ inthe wall of the retaining bore 631a, the pair of openings 632a₁₁ and632a₁₂ in the outer tubular member 632a₁ and the guide bore 618 in thewall of the binocular body 631 are formed with slight room, because theendless belt 619 is also moved with movement of the inner tubular member632a₂.

Only the left-hand lens-barrel unit 632 of the binocular illustrated inFIGS. 44 and 45 has been described. However, the same technical conceptis applied to the right-hand lens barrel unit 637. That is, theright-hand lens-barrel unit 647 is composed of the objective lens-barrel647a, an image-erecting chamber section 648 and an eyepiece lens-barrel647b, which correspond respectively to the objective lens-barrel 632a,the image-erecting chamber section 636 and the eyepiece lens-barrel632b.

FIG. 46 shows a modified form of the focusing mechanism illustrated inFIGS. 44 and 45. The focusing mechanism shown in FIG. 46 is differentfrom that shown in FIGS. 44 and 45 only in that a belt 619a having twofree ends is employed in place of the endless belt 619. Specifically,the belt 619a has opposite ends which are fixedly connected respectivelyto the outer periphery of the left-hand inner tubular member 632a₂ andto the outer periphery of the right-hand inner tubular member 671.

FIG. 47 shows another modified form of the focusing mechanismillustrated in FIGS. 44 and 45. The focusing mechanism shown in FIG. 47includes an operating roller 643b mounted to the binocular body 631 forangular movement relative thereto about an axis of the operating roller643b. Gear teeth 643b₁ are formed on an outer periphery of the operatingroller 643b. Likewise, gear teeth 632a₂₅ are formed on the outerperiphery of the inner tubular member of either one of the left- andright-hand objective lens-barrels 632a and 647a, that is, on the outerperiphery of the inner tubular member 632a₂ of the left-hand objectivelens-barrel 632a in the illustrated modification. The gear teeth 632a₂₅on the inner tubular member 632a₂ are in mesh with the gear teeth 643b₁on the operating roller 643b. A belt 619b having both ends free isassociated with the pair of inner tubular members 632a₂ and 672 and hasopposite ends which are fixedly connected respectively to the outerperipheries of the respective inner tubular members 632a₂ and 672.Meshing engagement between the gear teeth 643b₁ on the operating roller643b and the gear teeth 632a₂₅ on the inner tubular member 632a₂transmits the angular movement of the operating roller 632b to the innertubular member 632a₂ to angularly move the inner tubular member 632a₂about its axis relatively to the outer tubular member 632a₁. Moreover,the belt 619b transmits the angular movement of the left-hand innertubular member 632a₂ to the right-hand inner tubular member 672 therebyangularly moving the right-hand inner tubular member 672 about its axisrelative to the outer tubular member 673. In this manner, the focus isadjusted.

FIG. 48 shows a modified form of the binocular in which the technicalconcept described with reference to FIGS. 40 through 44 is applied tothe binocular shown in FIGS. 31 through 35. That is, the objectivelens-barrel 432a is formed separately from the image-erecting chambersection 436. Helicoid threads 611 are formed in the wall surface of theretaining bore 431a in the binocular body 432, while helicoid threads612 are formed in the outer periphery of the objective lens-barrel 432.The objective lens-barrel 432 and the wall surface of the retaining bore431a are threadedly engaged with each other through the helicoid threads611 and 612. The binocular body 431 is formed therein with a bore 401 sotapered as to diverge away from the objective lens-barrel 432a. Thetapered bore 401 in the binocular body 431 is aligned with the opticalaxis 1 of the objective lens system 433. The image-erecting chambersection 436 is provided with a hollow projection 402 which is alignedwith the optical axis 1 of the objective lens system 433. The hollowprojection 402 has an outer periphery which is tapered in complementaryrelation to the tapered bore 401 in the binocular body 431. The taperedhollow projection 402 is fitted in the tapered bore 401 in the binocularbody 431 so that the outer periphery of the hollow projection 402 is insliding contact with the tapered bore 401 in the binocular body 431.

FIGS. 49 through 54 shows a modified form of the binocular illustratedin FIGS. 13 through 18. In FIGS. 49 through 54, components and partslike or similar to those illustrated in FIGS. 13 through 18 aredesignated by the same or like reference numerals, and the descriptionof such like or similar components and parts will therefore be omittedto avoid repetition.

The binocular illustrated in FIGS. 49 through 54 is different from thebinocular shown in FIGS. 13 through 18 in that no interlocking mechanismis provided, but an improved focusing mechanism is incorporated.Specifically, as shown in FIG. 54, the projecting portion of theintermediate wall structure 766 of the binocular body 731 is providedwith a pair of spaced wall sections 766a and 766b between which anaccommodating space 766c is defined. A semi-circular bearing recess 721is formed in the top face of the wall section 766a. Likewise, asemi-circular bearing recess 722 is formed in the top face of the wallsection 766b in aligned relation to the bearing recess 721. An operatingroller 743 is composed of a roller body 743a and a pair of shaftsections 743b and 743b which project respectively from opposite endfaces of the roller body 743a in integral relation thereto. The shaftsections 743b and 743b are aligned with each other, and are receivedrespectively in the bearing recesses 721 and 722 such that the rollerbody 743a is accommodated in the accommodating space 766c and such thatthe operating roller 743 is angularly movable about an axis parallel tothe optical axis 1 of the objective lens system 733.

Like the focusing mechanism described previously with reference to FIGS.13 through 18, the operating roller 743 is formed with threads throughbore 743c, and a threaded shaft 744 threadedly engaged with the threadedbore 743c in the operating roller 743. The threaded shaft 744 has an endportion remote from the operating roller 743, which extends into asecond accommodating space 766d formed in the binocular body 731. Amovable block member 745 is mounted to the end portion of the threadedshaft 744 so as to prevent angular movement relative to the threadedshaft 744 about the axis thereof. As shown in FIG. 51, a pair ofinterlocking arms 746a and 746b have respective one ends fixedly mountedto the movable block member 745. The interlocking arm 746a extendslaterally through an opening 731a₁ formed in the wall of the retainingbore 731a and through an opening 732a₁₁ formed in the outer tubularmember 732a₁ of the objective lens-barrel 732a. The interlocking arm746a has a forward end which is received in an arcuate groove 732a₂₁formed in the outer periphery of the inner tubular member 732a₂ of theobjective lens-barrel 732a.

As shown in FIGS. 52 and 54, the movable block member 745 has a lowerportion thereof which is fitted in between a pair of guide projections731c and 731d formed on the intermediate wall structure 766 of thebinocular body 731 in such a manner that the block member 745 is movablealong the projections 731c and 731c while being guided thereby.

The binocular illustrated in FIGS. 49 through 54 has a retaining covermember 725 which is mounted to the top face of the binocular body 731for preventing the shaft sections 743b and 743b of the operating roller743 from coming out of the respective bearing recesses 721 and 722. Theretaining cover member 725 is formed therein with an opening 725athrough which the roller body 743a of the operating roller 743 ispartially exposed when the focusing mechanism is incorporated in thebinocular body 731 and the retaining cover member 725 is mounted to thetop face of the binocular body 731.

Incorporation of the focusing mechanism in the binocular body 731 iscarried out after the left- and right-hand lens-barrel units 732 and 747have been incorporated in the binocular body 731. That is, after boththe lens-barrel units 732 and 747 have been incorporated in thebinocular body 731, the focusing mechanism into which the variouscomponents are assembled is incorporated in the binocular body 731 insuch a manner that the shaft sections 743b and 743b of the operatingroller 743 are fitted respectively into the bearing recesses 721 and722; the movable block member 745 is accommodated in the accommodatingspace 766d; the interlocking arm 746a is fitted into the arcuate groove732a₂₁ in the inner tubular member 732a₂ through the opening 731a₁ inthe wall of the retaining bore 731a in the binocular body 731 andthrough the opening 732a₁₁ in the outer tubular member 732a₁ ; and,subsequently, the retaining cover member 725 is mounted to the top faceof the binocular body 731.

The operation of the focusing mechanism incorporated in the binocularshown in FIGS. 49 through 54 is substantially the same as that describedwith reference to FIGS. 13 through 18, and will not be repeated here.

Only the left-hand lens-barrel unit 732 of the binocular illustrated inFIGS. 49 and 54 has been described. However, the same technical conceptis applied to the right-hand lens barrel unit 747. That is, theright-hand lens-barrel unit 747 is composed of an objective lens-barrel747a, an image-erecting chamber section 748 and an eyepiece lens-barrel747b, which correspond respectively to the objective lens-barrel 732a,the image-erecting chamber section 736 and the eyepiece lens-barrel732b.

FIGS. 55 and 56 show a modified form of the binocular according to theinvention, in which a single objective lens-barrel is formed separatelyfrom a pair of image-erecting chamber sections in common relationthereto.

As shown in FIGS. 55 and 56, the binocular comprises a binocular body831 in the form of a disc, a pair of image-erecting chamber sections 836and 848, a pair of eyepiece lens-barrels 832b and 847b, and a singleobjective lens-barrel 832a common to the pair of image-erecting chambersections 836 and 848 and formed separately therefrom. The pair ofimage-erecting chamber sections 836 and 848 are angularly movableindependently of each other relatively to the disc-shaped binocular body831, subsequently to be described.

The disc-shaped binocular body 831 has an outer periphery which isformed with helicoid threads 831a. The objective lens-barrel 832a has aninner periphery formed with helicoid threads 832a₁ which are threadedlyengaged with the helicoid threads 831a on the disc-shaped binocular body831. Threaded engagement between the helicoid threads 831a and 832a₁enables the objective lens-barrel 832a to be angularly moved relativelyto the disc-shaped binocular body 831 about an axis thereof in such amanner that the objective lens-barrel 832a is reciprocatively movedrelatively to the disc-shaped binocular body 83a along the axis thereof.The objective lens-barrel 832a has incorporated therein an objectivelens system 833 which has a pair of optical axes 1 and 1' passingtherethrough in parallel relation to each other.

As shown in FIG. 55, the disc-shaped binocular body 831 is formedtherein with a pair of bores 801a and 801b so tapered as to diverge awayfrom the objective lens system 833. The tapered bores 801a and 801b inthe binocular body 831 are aligned respectively with the optical axes 1and 1' of the objective lens system 833.

The image-erecting chamber section 836 has incorporated therein a pairof known prism systems 837 and 838 for erecting an image and foroptically connecting the optical axis 1 and 1' of the respectiveobjective lens system 833 respectively to optical axes of the respectiveeyepiece lens systems 839 and 871 incorporated respectively in the pairof eyepiece lens barrels 832b and 847b. The image-erecting chambersection 836 has one end wall 861 which is formed therein with a bore 863aligned with the optical axis 1 of the objective lens system 833. A bore864 formed in the other end wall 862 of the image-erecting chambersection 836 is aligned with an optical axis of the eyepiece lens system839.

The image-erecting chamber section 836 is provided with a hollowprojection 802 which is aligned with the optical axis 1 of the objectivelens system 833. The hollow projection 802 has an outer periphery whichis tapered in complementary relation to the tapered bore 801a in thebinocular body 831. The tapered hollow projection 802 is fitted in thetapered bore 801a in the disc-shaped binocular body 831 in such a mannerthat the outer periphery of the hollow projection 802 is in slidingcontact with the tapered bore 801a in the disc-shaped binocular body831.

The hollow projection 802 has a forward end PG,62 projecting from an endface of the disc-shaped binocular body 831 adjacent the objective lenssystem 833. A retaining ring 806, such as a screw nut is arranged at theend face of the disc-shaped binocular body 831 and is threadedly engagedwith an outer periphery of the forward end of the hollow projection 802,to prevent the hollow projection 802 from coming out of the tapered bore801 in the disc-shaped binocular body 831.

Because of threaded engagement between the helicoid threads 831a and832a₁, angular movement of the objective lens-barrel 832a about its axisrelative to the disc-shaped binocular body 831 causes the objective lenssystem 833 to be reciprocatively moved along the optical axes 1 and 1'relatively to the disc-shaped binocular body 831, thereby enabling thefocus to be adjusted.

In the binocular illustrated in FIGS. 55 and 56, when it is desired toadjust the distance between the eyepiece lens-barrels 832b and 847b tomatch the distance between the observer's eyes, the pair ofimage-erecting chamber sections 836 and 848 are angularly movedrelatively to the disc-shaped binocular body 831 about the respectiveoptical axes 1 and 1' of the objective lens system 833.

As shown in FIGS. 55 and 56, the disc-shaped binocular body 831 isprovided at its center with a through bore 895. The through bore 895 maybe rectangular or circular in shape, or may have any other suitableshape. The through bore 895 cooperates with the objective lens system833 to form a magnifying glass unit. As shown in FIG. 56, the throughbore 895 is arranged between the pair of image-erecting chamber sections832b and 847b. The through bore 895 is covered with a dust-proof closure896 which is removable from the through bore 895 when it is desired toutilize the binocular as the magnifying glass unit.

When the binocular is employed as the magnifying glass unit, thedust-proof closure 896 is removed from the through bore 895.Subsequently, as indicated by the double-dotted lines in FIG. 55, thebinocular is placed on a table 897 in such a manner that the pair ofeyepiece lens-barrels 832b and 847b are in contact with the table 897and in such a manner that the through bore 895 faces an object 898 to beobserved. In such a set position, if the objective lens system 833 isviewed from above, the observer can view the object 898 magnified. Thatis to say, the binocular can be utilized as a magnifying lens unitenabling an observer to view insects, postal stamps, fossils, figures,characters or the like in a magnified scale.

Alternatively, as shown in FIG. 57, the through bore 895a may be formedin the binocular body 831 at a location adjacent the periphery thereof.The through bore 835 is arranged on a line passing through a locationbetween the pair of image-erecting chamber sections 836 and 848. Thearrangement illustrated in FIG. 57 enables the pair of image-erectingchamber sections 836 and 848 to be arranged in close relation to eachother, making it possible to reduce the diameter of the objectivelens-barrel 832a.

Only the left-hand lens-barrel unit 832 of the binocular illustrated inFIGS. 55 and 56 has been described. However, the same technical conceptis applied to the right-hand lens barrel unit 847.

The binocular described above with reference to FIGS. 55 through 56 orFIG. 57 is advantageous in that provision of the single objectivelens-barrel 833 common to the left- and right-hand image-erectingchamber sections 836 and 848 enables the focusing mechanism to besimplified in construction. Further, the optical axes 1 and 1' arealways maintained stationary during angular movement of the eyepiecelens-barrels 832b and 847b, and the distance between the optical axes 1and 1' is maintained unchanged. Moreover, the binocular is extremelyconvenient, because it is provided with the magnifying lens function forviewing various objects to be observed such as insects, postal stamps orthe like in an magnified scale. The binocular has other variousadvantages similar to those mentioned previously.

FIGS. 58 through 60 show a modified form of the binocular illustrated inFIGS. 55 and 56. In FIGS. 58 through 60, components and parts like orsimilar to those illustrated in FIGS. 55 and 56 are designated by thesame or like reference numerals, and the description of such like orsimilar components and parts will therefore be omitted to avoidrepetition.

The binocular illustrated in FIGS. 58 through 60 comprises a zoomobjective lens-barrel. Specifically, as shown in FIG. 58, the binocularbody 931 is integrally provided with a cylindrical wall 961 projectingfrom the end face of the binocular body 931 remote from theimage-erecting chamber sections 836 and 848.

The zoom objective lens-barrel 932a is composed of a pair of inner andouter tubular members 932a₂ and 932a₁ in concentric relation to eachother. The inner and outer tubular members 932a₂ and 932a₁ haveincorporated therein their respective objective lens system sections933b and 933a arranged in coaxial relation to each other. The innertubular member 932a₂ is arranged within the cylindrical wall 961 of thebinocular body 931 for angular movement relative thereto about the axisof the cylindrical wall 961 and for reciprocative movement relative tothe cylindrical wall 961 along the axis thereof. A movable intermediatetubular member 962 is arranged about the outer periphery of thecylindrical wall 961 for reciprocative movement along the axis thereof,but against angular movement relative to the cylindrical wall 961 alongthe axis thereof.

A cam pin 963 projects radially outwardly from the inner tubular member932a₂. The cam pin 963 extends through an elongated guide slot 961aformed in the cylindrical wall 961 of the binocular body 931. A keygroove 961b is formed in the outer periphery of the cylindrical wall 961and serves to allow the movable intermediate tubular member 962 to belinearly and reciprocatively moved relatively to the cylindrical wall961 along the axis thereof without angular movement thereaboutsubsequently to be described.

The movable intermediate tubular member 962 is formed therein with anelongated cam slot 962a serving to urge the cam pin 963. Theintermediate tubular member 962 is provided on its inner periphery witha key 962b which projects into the key groove 961b formed in thecylindrical wall 961. The intermediate tubular member 962 has one endportion remote from the image-erecting chamber sections 836 and 848. Theone end portion of the intermediate tubular member 962 has an outerperipheral surface formed with helicoid threads 962c. The outer tubularmember 932a₁ of the objective lens-barrel 932a has an inner peripheryformed with helicoid threads 964 which are threadedly engaged with thehelicoid threads 962c on the intermediate tubular member 962. Moreover,the intermediate tubular member 962 has the other end portion adjacentthe image-erecting chamber sections 836 and 848. The other end portionof the intermediate tubular member 962 has an outer peripheral surfaceformed with threads 962d small in pitch which extend circumferentiallyof the intermediate tubular member 962.

An operating tubular member 965 is arranged about the outer periphery ofthe movable intermediate tubular member 962, with the outer tubularmember 932a₁ of the objective lens-barrel 932a positioned therebetween.The operating tubular member 965 has an inner periphery formed withthreads 965a which are threadedly engaged with the threads 962d on theintermediate tubular member 962. The operating tubular member 965 isprovided with a stopper pin 965e projecting radially inwardly. On theother hand, the movable intermediate tubular member 962 is provided onits outer periphery with an arcuate stopper projection 962e extendingcircumferentially. The stopper pin 965e on the operating tubular member965 is capable of being abutted against the arcuate stopper projection962e to determine the angular movement range of the operating tubularmember 965.

The operating tubular member 965 is reciprocatively movable togetherwith the movable intermediate tubular member 962 along the axis of thecylindrical wall 961. The operating tubular member 965 is provided witha radially inwardly projecting pin 965f located adjacent the end of theoperating tubular member 965 remote from the image-erecting chambersections 836 and 848. The projecting pin 965f is movable along an axialstraight groove 966 formed in the outer periphery of the outer tubularmember 932a₁ of the objective lens-barrel 933a.

As mentioned previously, the helicoid threads 964 on the outer tubularmember 932a₁ of the objective lens-barrel 932a are threadedly engagedwith the helicoid threads 962c on the movable intermediate tubularmember 962. Because of the engagement between the helicoid threads 964and 962c, angular movement of the operating tubular member 965 about thecylindrical wall 961 causes the outer tubular member 932a₁ to be movedreciprocatively along the axis of the cylindrical wall 961, therebymoving the objective lens system section 933a incorporated in the outertubular member 932a₁ toward and away from the objective lens section933b incorporated in the inner tubular member 932a₂.

Additionally, a cover 967 is mounted to the binocular body 931 and has acylindrical projecting wall 967a which is arranged between the movableintermediate tubular member 962 and the operating tubular member 965.

The operation of the binocular illustrated in FIGS. 58 through 60 willbe described with reference to FIGS. 59 and 60. FIG. 59 shows thepositional relationship of the cylindrical wall 961, the inner tubularmember 932a₂ of the objective lens-barrel 932a, and the movableintermediate tubular member 962 when the objective lens-barrel 932aoccupies a telescopic position, while FIG. 60 shows the positionalrelationship of these components when the objective lens-barrel 932aoccupies a wide-angle position.

When the operating tubular member 965 is in the position closest to theimage-erecting chamber sections 836 and 848 as shown in FIG. 58, thevarious components are in the positional relationship illustrated inFIG. 59, and the objective lens-barrel 932a is in the telescopicposition where the objective lens system sections 933b and 933aincorporated respectively in the inner and outer tubular members 932a₂and 932a₁ are reduced in distance therebetween.

As the operating tubular member 965 is linearly moved forwardly awayfrom the image-erecting chamber sections 836 and 848 along the axis ofthe stationary cylindrical wall 961, the movable intermediate tubularmember 962 threadedly engaged with the operating tubular member 965through the threads 962d and 965a is also moved together therewith,causing the cam slot 962a to urge the cam pin 963. During the forwardmovement of the operating tubular member 965, the key 962b is movedalong the key groove 961b to prevent angular movement of the movableintermediate tubular member 962. That is, the cam pin 963 urged by thecam slot 962a is moved angularly while being guided along the guide slot961a. This operation gradually increases the distance between the innertubular member 932a₂ of the objective lens-barrel 932a to which the campin 963 is mounted, and the outer tubular member 932a₁ which is movedtogether with the operating tubular member 965. In this manner, thezooming operation is carried out which corresponds to the movingposition of the operating tubular member 965. As the operating tubularmember 965 is moved to a position farthest from the image-erectingchamber sections 836 and 848, the various components occupy theirrespective positions illustrated in FIG. 59. Thus, the objectivelens-barrel 832a occupies the wide-angle position where the distance islong between the objective lens system sections 933b and 933a of therespective inner and outer tubular members 932a₂ 932₁ 1.

In the wide-angle position, if the operating tubular member 965 is movedin the direction opposite to that described above, i.e., toward theimage-erecting chamber sections 836 and 848, the distance between theobjective lens system sections 933a and 933b is gradually reduced, sothat the objective lens-barrel 932b moves toward the telescopicposition.

On the other hand, when the operating tubular member 965 is angularlymoved relatively to the stationary cylindrical wall 961 about the axisthereof, the operating tubular member 965 is angularly moved about themovable intermediate tubular member 962 within the range in which thestopper pin 965e is restricted by the stopper projection 962e. That is,the operating tubular member 965 is angularly moved while the threads965a on the operating tubular member 965 are threadedly engaged with thethreads 962d on the intermediate tubular member 962 maintainedstationary.

As a result, angular movement of the projecting pin 965f on theoperating tubular member 965 which projects into the linear groove 966in the outer tubular member 932a₁ causes the same to be angularly movedabout the stationary cylindrical wall 961. Because of the threadedengagement between the helicoid threads 962c and 964, the outer tubularmember 932a₁ is moved reciprocatively along the axis of the cylindricalwall 961. In this manner, angular movement operation of the operatingtubular member 965 varies the position of the objective lens systemsection 933a incorporated in the outer tubular member 932a, relative tothe objective lens system section 933b incorporated in the inner tubularmember 932a₂. Thus, focusing is carried out with respect to the left-and right-hand lens-barrel units 932 and 947.

The binocular illustrated in FIGS. 58 through 60 is also utilized as amagnifying lens unit like the binocular shown in FIGS. 55 and 56. Thatis, a through bore 995 is formed in the binocular body 931, and iscovered with a dust-proof closure 996.

The binocular illustrated in FIGS. 58 through 60 may comprises ainterlocking mechanism like that described previously with reference toFIG. 19. That is, as shown in FIG. 61, the pair of toothed plates 951aand 951b are fixedly mounted respectively to the outer peripheries ofthe respective image-erecting chamber sections 836 and 848. The toothedplates 951a and 951b are mounted respectively to the image-erectingchamber sections 836 and 848 at respective locations adjacent the endwalls 861 and 891 of the respective image-erecting chamber sections 836and 847. The pair of toothed plates 951a and 951b are in mesh with eachother so that the pair of eyepiece lens-barrels 832b and 847b areinterlocked with each other.

The binocular described above with reference to FIGS. 58 through 60 orFIG. 61 has advantages similar to those obtained by the binocularillustrated in FIGS. 55 and 56. Furthermore, it is not required for thebinocular that a pair of zooming mechanisms be provided respectively fora pair of left- and right-hand objective lens-barrels like theconventional binocular. Accordingly, the binocular of the invention canbe simplified in construction.

What is claimed is:
 1. A binocular comprising:a binocular body; a pairof objective lens-barrels, each having an objective lens positionedwithin a respective lens-barrel, each objective lens including arespective optical axis extending parallel to each other, said pair ofobjective lens-barrels being mounted within said binocular body forangular movement relative thereto about the respective optical axes; apair of eyepiece lens-barrels including respective eyepiece lenses, saideyepiece lenses having respective optical axes extending parallel to therespective optical axes of said objective lenses, each of said eyepiecelens-barrels being adapted to move with respect to said binocular bodyabout a corresponding one of said pair of optical axes of said objectivelenses in such a manner that said optical axes of the respectiveeyepiece lenses are respectively movable towards and away from eachother about said pair of optical axes of said objective lenses; and apair of image-erecting chambers, each chamber being arranged between anobjective lens-barrel and a corresponding one of said eyepiecelens-barrels, said eyepiece lens-barrels extending from said pair ofimage-erecting chambers, each image-erecting chamber including opticalmeans for optically connecting said optical axes of said objectivelenses with the optical axes of the respective eyepiece lens, said pairof image-erecting chambers being fixedly connected respectively to saidpair of objective lens-barrels for angular movement together therewithrelative to said binocular body about the respective optical axes ofsaid pair of objective lenses.
 2. The binocular according to claim 1,wherein said pair of image-erecting chambers are angularly movableindependently of each other about said optical axes of the respectiveobjective lenses.
 3. The binocular according to claim 2, wherein saidbinocular body is formed therein with a pair of retaining bores, saidpair of objective lens-barrels being accommodated, respectively, in saidpair of retaining bores for angular movement relative to said binocularbody about the respective optical axes of said pair of objective lenses,and wherein said binocular further comprises support plate means mountedto said binocular body for supporting the end faces of the respectiveimage-erecting chambers that are remote from the respective objectivelens-barrels.
 4. The binocular according to claim 2, wherein saidsupport plate means comprises a single support plate common to said pairof image-erecting chambers.
 5. The binocular according to claim 4, whichfurther comprises a pair of bearings arranged between said commonsupport plate and the respective end faces of said pair ofimage-erecting chambers said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 6. Thebinocular according to claim 5, wherein each of said pair of bearingscomprises a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 7. Thebinocular according to claim 3, wherein each of said retaining bores hasan end portion remote from a corresponding one of said pair ofimage-erecting chambers, said end portion of the retaining bore beingtapered so as to converge, wherein each of said pair of objectivelens-barrels has an end portion remote from a corresponding one of saidpair of image-erecting chambers, said end portion of the objectivelens-barrel being tapered in complementary relation to the tapered endportion of a corresponding one of said retaining bores, and wherein saidsupport plate means urges said pair of image-erecting chambers andtherefore said objective lens-barrels so that the tapered end portionsof the respective objective lens-barrels are in sliding contactrespectively with the tapered end portions of the respective retainingbores.
 8. The binocular according to claim 1, wherein said binocularbody is formed therein with a pair of retaining bores, said pair ofobjective lens-barrels being accommodated respectively in said pair ofretaining bores for angular movement relative to said binocular bodyabout the respective optical axes of said pair of objective lenses, andwherein said binocular further comprises support plate means mounted tosaid binocular body for supporting end faces of the respectiveimage-erection chambers that are remote from the respective objectivelens-barrels.
 9. The binocular according to claim 8, wherein saidsupport plate means comprises a single support plate common to said pairof image-erecting chambers.
 10. The binocular according to claim 9,which further comprises a pair of bearings arranged between said commonsupport plate and the respective end faces of said pair ofimage-erecting chambers, said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 11. Thebinocular according to claim 10, wherein each of said pair of bearingsis composed of a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 12. Thebinocular according to claim 9, which further comprises a plurality offastening screws, wherein said support plate is secured onto said endfaces of the respective image-erecting chambers while exertingrotational frictional force between each of said pair of image-erectingchambers and said support plate, and wherein said rotational frictionalforce is controlled by adjusting the fastening amount of said fasteningscrews.
 13. A binocular comprising:a binocular body; a pair of objectivelens-barrels being mounted on said binocular body, each of said pair ofobjective lens-barrels having an outer tubular member and an innertubular member accommodated in the outer tubular member in concentricrelation thereto, angular movement being prevented relative to the outertubular member about an axis of said inner tubular member, but allowingreciprocal movement relative to said outer tubular member along the axisof the inner tubular member, a pair of objective lenses having theirrespective optical axes extending parallel to each other, said pair ofobjective lenses being incorporated respectively in the inner tubularmembers of the respective objective lens-barrels in such a manner thatthe axes of the inner tubular members of the respective lens-barrels arecoincident with the respective optical axes of said pair of objectivelenses; a pair of eyepiece lens-barrels including respective eyepiecelenses, said eyepiece lenses having respective optical axes extendingparallel to the respective optical axes of said objective lenses, eachof said eyepiece lens-barrels being adapted to move with respect to saidbinocular body about a corresponding one of said pair of optical axes ofsaid objective lenses in such a manner that said optical axes of therespective eyepiece lenses are respectively movable towards and awayfrom each other about said pair of optical axes of said objectivelenses; and a pair of image-erecting chambers, each chamber beingarranged between an objective lens-barrel and a corresponding one ofsaid eyepiece lens-barrels, said eyepiece lens-barrels extending fromsaid pair of image-erecting chambers, each image-erecting chamberincluding optical means for optically connecting said optical axes ofsaid objective lenses with the optical axes of the respective eyepiecelens, wherein said pair of image-erecting chambers is fixedly connectedrespectively to the outer tubular members of the respective objectivelens-barrels for angular movement together therewith, relative to saidbinocular body about the respective optical axes of said pair ofobjective lenses.
 14. The binocular according to claim 13, furthercomprising interlocking means arranged between said pair ofimage-erecting chambers for interlocking them with each other in such amanner that said pair of eyepiece lens-barrels are movable angularly intheir respective directions opposite to each other about the respectiveone of said pair of optical axes of the objective lens.
 15. Thebinocular according to claim 14, wherein said binocular body is formedtherein with a pair of retaining bores, said pair of objectivelens-barrels being accommodated respectively in said pair of retainingbores such that said outer tubular members of the respective objectivelens-barrels are angularly movable relative to said binocular body aboutthe respective optical axes of said pair of objective lenses, andwherein said binocular further comprises support plate means mounted tosaid binocular body for supporting the end faces of the respectiveimage-erecting chambers that are remote from the respective objectivelens-barrels.
 16. The binocular according to claim 15, wherein saidsupport plate means comprises a single support plate common to said pairof image-erecting chambers.
 17. The binocular according to claim 16,which further comprises a pair of bearings arranged between said commonsupport plate and the respective end faces of said pair ofimage-erecting chambers, said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 18. Thebinocular according to claim 17, wherein each of said pair of bearingscomprises a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 19. Thebinocular according to claim 13, wherein each of said retaining boreshas an end portion remote from a corresponding one of said pair ofimage-erecting chambers, said end portion of the retaining bore beingtapered so as to converge, wherein the outer tubular member of each ofsaid pair of objective lens-barrels has an end portion remote from acorresponding one of said pair of image-erecting chambers, the endportion of the outer tubular member being tapered in complementaryrelation to the tapered end portion of a corresponding one of said pairof retaining bores, and wherein said support plate means urges saidimage-erecting chambers and therefore said objective lens-barrels sothat the tapered end portions of the respective outer tubular membersare in sliding contact with the tapered end portions of the respectiveretaining bores.
 20. The binocular according to claim 13, wherein saidpair of image-erecting chambers are angularly movable independently ofeach other about said optical axes of the respective objective lens. 21.The binocular according to claim 20, wherein said binocular body isformed therein with a pair of retaining bores, said pair of objectivelens-barrels being accommodated respectively in said pair of retainingbores for angular movement relative to said binocular body about therespective optical axes of said pair of objective lenses, and whereinsaid binocular further comprises support plate means mounted to saidbinocular body for supporting end faces of the respective image-erectingchambers that are remote from the respective objective lens-barrels. 22.The binocular according to claim 21, wherein said support plate meanscomprises a single support plate common to said pair of image-erectingchambers.
 23. The binocular according to claim 22, which furthercomprises a pair of bearings arranged between said common support plateand the respective end faces of said pair of image-erecting chambers,said bearings being arranged respectively on extension lines of therespective optical axes of said pair of objective lenses.
 24. Thebinocular according to claim 23, wherein each of said pair of bearingmeans is composed of a ball received in a recess formed in the end faceof a corresponding one of said pair of image-erecting chambers.
 25. Abinocular comprising:a binocular body; a pair of objective lens-barrels,each having an objective lens positioned within a respectivelens-barrel, each objective lens including a respective optical axisextending parallel to each other, said binocular body being formedtherein with a pair of retaining bores, said pair of objectivelens-barrels being accommodated respectively in said pair of retainingbores for angular movement relative to said binocular body about therespective optical axes of said pair of extended lenses; a pair ofeyepiece lens-barrels including respective eyepiece lenses, saideyepiece lenses having respective optical axes extending parallel to therespective optical axes of said objective lenses, each of said eyepiecelens-barrels being adapted to move with respect to said binocular bodyabout a corresponding one of said pair of optical axes of said objectivelenses in such a manner that said optical axes of the respectiveeyepiece lenses are respectively movable towards and away from eachother about said pair of optical axes of said objective lenses; a pairof image-erecting chambers, each chamber being arranged between anobjective lens-barrel and a corresponding one of said eyepiecelens-barrels, said eyepiece lens-barrels extending from said pair ofimage-erecting chambers, each image-erecting chamber including opticalmeans for optically connecting said optical axes of said objectivelenses with the optical axes of the respective eyepiece lens; and asupport plate mounted to said binocular body for supporting end faces ofthe respective image-erecting chambers that are remote from therespective objective lens-barrels, said support plate being common tosaid pair of image-erecting chambers, and a pair of bearings arrangedbetween said common support plate and the respective end faces of saidimage-erecting chambers, said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 26. Thebinocular according to claim 25, wherein each of said pair of bearingscomprises a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 27. Thebinocular according to claim 25, wherein said common support plate isprovided with a pair of recesses formed on its surface facing said endfaces of the pair of image-erecting chambers, said pair of recessesbeing arranged respectively to be on one of said extension lines whensaid common support plate is mounted on said binocular body, each ofsaid end faces is provided with a recess arranged on the correspondingone of said extension lines; andwherein each of said pair of bearings isreceived between the corresponding one of said pair of recesses of thecommon support plate and the recess of each of said end faces, therebyregulating the positional relationship between said pair ofimage-erecting chambers in such a manner that said pair of optical axesof the objective lenses become parallel to each other, while each ofsaid image-erecting chambers is able to angularly move about therespective one of said optical axes of the objective lens.
 28. Abinocular comprising:a binocular body; a pair of objective lens-barrels,each having an objective lens positioned within a respectivelens-barrel, each objective lens including a respective optical axisextending parallel to each other, said pair of objective lens-barrelsbeing connected to said binocular body for angular movement relativethereto about the respective optical axes; a pair of eyepiecelens-barrels including respective eyepiece lenses, said eyepiece lenseshaving respective optical axes extending parallel to the respectiveoptical axes of said objective lenses, each of said eyepiecelens-barrels being adapted to move with respect to said binocular bodyabout a corresponding one of said pair of optical axes of said objectivelenses in such a manner that said optical axes of the respectiveeyepiece lenses are respectively movable towards and away from eachother about said pair of optical axes of said objective lenses; and apair of image-erecting chambers, each chamber being arranged between anobjective lens-barrel and a corresponding one of said eyepiecelens-barrels, said eyepiece lens-barrels extending from said pair ofimage-erecting chambers, each image-erecting chamber including opticalmeans for optically connecting said optical axes of said objectivelenses with the optical axes of the respective eyepiece lens, said pairof image-erecting chambers being fixedly connected respectively to saidpair of objective lens-barrels for angular movement together therewithrelative to said binocular body about the respective optical axes ofsaid pair of objective lenses.
 29. The binocular according to claim 28,wherein said pair of image-erecting chambers are angularly movableindependently of each other about said optical axes of the respectiveobjective lenses.
 30. The binocular according to claim 29, wherein saidbinocular body is formed therein with a pair of retaining bores, saidpair of objective lens-barrels being accommodated, respectively, in saidpair of retaining bores for angular movement relative to said binocularbody about the respective optical axes of said pair of objective lenses,and wherein said binocular further comprises support plate means mountedto said binocular body for supporting the end faces of the respectiveimage-erecting chambers that are remote from the respective objectivelens-barrels.
 31. The binocular according to claim 29, wherein saidsupport plate means comprises a single support plate common to said pairof image-erecting chambers.
 32. The binocular according to claim 31,which further comprises a pair of bearings arranged between said commonsupport plate and the respective end faces of said pair ofimage-erecting chambers said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 33. Thebinocular according to claim 32, wherein each of said pair of bearingscomprises a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 34. Thebinocular according to claim 30, wherein each of said retaining boreshas an end portion remote from a corresponding one of said pair ofimage-erecting chambers, said end portion of the retaining bore beingtapered so as to converge, wherein each of said pair of objectivelens-barrels has an end portion remote from a corresponding one of saidpair of image-erecting chambers, said end portion of the objectivelens-barrel being tapered in complementary relation to the tapered endportion of a corresponding one of said retaining bores, and wherein saidsupport plate means urges said pair of image-erecting chambers andtherefore said objective lens-barrels so that the tapered end portionsof the respective objective lens-barrels are in sliding contactrespectively with the tapered end portions of the respective retainingbores.
 35. The binocular according to claim 28, wherein said binocularbody is formed therein with a pair of retaining bores, said pair ofobjective lens-barrels being accommodated respectively in said pair ofretaining bores for angular movement relative to said binocular bodyabout the respective optical axes of said pair of objective lenses, andwherein said binocular further comprises support plate means mounted tosaid binocular body for supporting end faces of the respectiveimage-erection chambers that are remote from the respective objectivelens-barrels.
 36. The binocular according to claim 35, wherein saidsupport plate means comprises a single support plate common to said pairof image-erecting chambers.
 37. The binocular according to claim 36,which further comprises a pair of bearings arranged between said commonsupport plate and the respective end faces of said pair ofimage-erecting chambers, said bearings being arranged on extension linesof the respective optical axes of said pair of objective lenses.
 38. Thebinocular according to claim 37, wherein each of said pair of bearingsis composed of a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 39. Thebinocular according to claim 36, which further comprises a plurality offastening screws, wherein said support plate is secured onto said endfaces of the respective image-erecting chambers while exertingrotational frictional force between each of said pair of image-erectingchambers and said support plate, and wherein said rotational frictionalforce is controlled by adjusting the fastening amount of said fasteningscrews.
 40. A binocular comprising:a binocular body; a pair of objectivelens-barrels, each having an objective lens positioned within arespective lens-barrel, each objective lens including a respectiveoptical axis extending parallel to each other, said binocular body beingformed therein with a pair of retaining means, said pair of objectivelens-barrels being respectively received by said pair of retaining meansfor angular movement relative to said binocular body about therespective optical axes of said pair of extended lenses; a pair ofeyepiece lens-barrels including respective eyepiece lenses, saideyepiece lenses having respective optical axes extending parallel to therespective optical axes of said objective lenses, each of said eyepiecelens-barrels being adapted to move with respect to said binocular bodyabout a corresponding one of said pair of optical axes of said objectivelenses in such a manner that said optical axes of the respectiveeyepiece lenses are respectively movable towards and away from eachother about said pair of optical axes of said objective lenses; a pairof image-erecting chambers, each chamber being arranged between anobjective lens-barrel and a corresponding one of said eyepiecelens-barrels, said eyepiece lens-barrels extending from said pair ofimage-erecting chambers, each image-erecting chamber including opticalmeans for optically connecting said optical axes of said objective lenswith the optical axes of the respective eyepiece lens; and a supportplate mounted to said binocular body for supporting end faces of therespective image-erecting chambers that are remote from the respectiveobjective lens-barrels, said support plate being common to said pair ofimage-erecting chambers, and a pair of bearings arranged between saidcommon support plate and the respective end faces of said image-erectingchambers, said bearings being arranged on extension lines of therespective optical axes of said pair of objective lenses.
 41. Thebinocular according to claim 40, wherein each of said pair of bearingscomprises a ball received in a recess formed in the end face of acorresponding one of said pair of image-erecting chambers.
 42. Thebinocular according to claim 40, wherein said common support plate isprovided with a pair of recesses formed on its surface facing said endfaces of the pair of image-erecting chambers, said pair of recessesbeing arranged respectively to be on one of said extension lines whensaid common support plate is mounted on said binocular body, each ofsaid end faces is provided with a recess arranged on the correspondingone of said extension lines; andwherein each of said pair of bearings isreceived between the corresponding one of said pair of recesses of thecommon support plate and the recess of each of said end faces, therebyregulating the positional relationship between said pair ofimage-erecting chambers in such a manner that said pair of optical axesof the objective lenses become parallel to each other, while each ofsaid image-erecting chambers is able to angularly move about therespective one of said optical axes of the objective lens.